1. Field of the Invention
The invention relates in general to a lamp structure, and more particularly to a lamp structure capable of increasing light emitting angle.
2. Description of the Related Art
In general, the LED light source, which provides illumination, can be used in various types of lamp structure such as the planar lamp device or the tubular lamp in majority. The planar lamp device has a light guide plate inside for refracting the light emitted by the LED light source disposed on the lateral side upwards so as to generate a planar light beam. The tubular lamp emits the light outwards through the light emitting surface of the LED light source directly. The shape of the cover of the tubular lamp is a curvature. However, due to the restrictions in the size and appearance of the cover, the design in the distance between light emitting surface of LEDs and the cover is poor and may cause visual problems or poor efficiency. If the distance is too short, hotspots may occur to the front side of the cover due to the concentration of the heat generated by the LEDs, and mura or spots may occur to the lateral sides of the cover due to an uneven distribution of luminance. Consequently, the uniformity and illumination range of the lamp are affected. On the other hand, if the distance is too large, the size and appearance of the lamp will be enlarged and the intensity of illumination will be insufficient. Consequently, more LEDs will be needed and the cost will be increased. Thus, the conventional lamp structure needs to be further improved no matter in terms of appearance or luminous uniformity.